On a transport network, a CC (client controller) manages a transport subnet, and a TC (transport controller) manages one or more CCs. The CC is equivalent to a tenant. A physical network resource is divided into a virtual network topology by the TC according to a tenant requirement, and then is provided to the tenant (CC). The TC maintains a physical network resource allocation status and global network topology information, and puts a resource that is not allocated to any CC into a resource pool for centralized scheduling and management.
The CC may control and manage its own virtual network topology resources. For example, a CC1 may allocate a path 1 in the virtual network topology resource to bear a service 1, and allocate a path 2 in the virtual network topology resource to bear a service 2. A resource that is not allocated to any service is put into a resource pool of the CC for centralized scheduling and management by the CC.
When the present invention creation is implemented, the inventor finds that, in many cases, the CC needs to perform online optimization on a service, for example, a service is adjusted from an original path to another path. When the online optimization is performed, an establishment-before-disconnection manner may be used: The CC establishes, by using an available virtual resource in a resource pool managed by the CC, an optimization path to bear a service and achieve performance optimization (which includes but is not limited to a delay, a hop count, and a cost). When the optimized service connection is successfully established, an original service path of the service is disconnected. Therefore, the online optimization may be completed without interrupting the service. However, when an available virtual network resource managed by the CC is insufficient, an establishment-before-disconnection procedure cannot be completed. Therefore, a network service cannot be optimized without interrupting a service.